Field of the Invention
This invention relates to fuels for internal combustion engines and more particularly to the provision of a novel multipurpose additive for such fuels.
As is well known, hydrocarbon fuels have a tendency to form polymeric materials (variously called "gum" or "sludge" or "varnish") in various parts of fuel systems. These resin-like deposits tend to form in the fuel supply lines, fuel filter, carburetor, fuel control injectors, intake manifold and valve stems. Such deposits are objectionable not only because of their effect on mechanical performance but also because they decrease the breathing efficiency in engines of the spark ignition type.
Although each type of fuel is composed essentially of hydrocarbons, the stability characteristics of fuels differ considerably. Thus, typical automotive fuels contain straight and branched chain compounds while aircraft fuels contain a smaller proportion of olefins. Currently, certain types of fuels contain increased amounts of cracked stocks resulting in a higher olefin content and an increased susceptibility to the formation of gum.
Although motor fuels are highly refined products but still contain minor amounts of impurities and water which can cause corrosion in the fuel tank, fuel lines and carburetor of a motor vehicle. Accordingly, commercial motor fuel compositions contain rust inhibitors and/or, antirust agents. Naturally, the economics of providing such fuels are improved if a single multipurpose additive can perform plural functions.